You probably have a bit more experience with it, are there any cross-browser issues with .getAttribute('value')?
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Felix KlingJul 27 '12 at 9:21

@FelixKling: I wouldn't trust IE as far as I could throw Steve Ballmer, particularly not IE7. Whereas I know that defaultValue has worked for 15 some-odd years. I think I tried getAttribute and found it to be unreliable, but I'd have to do an experiment to be sure.
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T.J. CrowderJul 27 '12 at 9:22

You could store default value in a data-container for the input element, then update that data-value when user clicks the get button (unless you always want to have access to default value and not just the last value).